Figure 5

False-negative specimen by the objective autofluorescence visualization method. (a) There was an outwardly growing lesion on the lateral edge of the tongue. (b) The lesion did not show apparent fluorescence visualization loss with fluorescent light emitted from the VELscope leading to low luminance ratio. One of the reasons could be that the lesion is located on the lateral edge of the tongue. Another reason could be possible genetic alteration of the specimen. (c) However, the lesion was iodine-unstained. (d) The histopathological diagnosis was squamous cell carcinoma (Specimen No. 2). Bar=500 μm.